Artificial tooth.



u. w. BLUNDELL, J. H. MILLS & A. T. MAGUIRE.

ARTIFICIAL TOOTH.

. APPLICATION FILED JAN. 4. I912.

1,21 1,81 7. Patented Jan. 9,1917.

WITNESSES INVENTORS'.

- ZDMWMWCBM BY A W (1AA) M THEIR A TORNEY IN FACT.

NITED STATES FFIQE.

DAVID WILLIAM BLUNDELL AND JOHN HENRY IVIILLS, OF EAST MOLLSEY, ANDALFRED THOMAS MAGrUIRE, OF LONDON, ENGLAND, ASSIGNORS T0 BRITISHDIATORIC MANU- FACTURING COMPANY LIMITED, OF EAST MOLESEY, ENGLAND.

ARTIFICIAL TOOTH.

Specification of Letters Patent.

Patented Jan. 9, 1917.

To all whom it may concern Be it known that we, DAVID WILLIAM BLUNDELL,JOHN HENRY Mums, and ALFRED THOMAS MAGUIRE, subjects of the King ofEngland, DAVID WILLIAM BLUNDELL and JOHN HENRY MILLS, residents of EastMolesey, in the county of Surrey, and ALFRED THOMAS MAGUIRE, resident of40 Bow Road, in the county of London, England, have invented new anduseful Improvements in or Relating to Artificial Teeth, of which thefollowing is a specification.

This invention relates to artificial teeth and has for its object toprovide improved constructions of teeth which can be easily and cheaplymanufactured and which permit of them being very firmly secured to abacking or plate for the purpose of forming a denture.

The important feature of our invention consists in the methods which weemploy for securing the anchoring pins in what are known as detachablepin teeth in which the anchoring pin is inserted in a cavity in thetooth after the latter has been baked.

In order that the invention may be clearly understood we will nowproceed to describe the same with reference to the accompanyingdrawings, in which I Figure l is a sectional view of an artificial toothattached to a backing with the aid of an anchoring pin which is securedto the tooth in accordance with our invention. Figs. 2 and 3 aresections of the tooth on lines V, V and V V respectively of Fig. 1before the same has been mounted on the backing. Fig. 4: is aperspective view of the anchoring pin. Fig. 5 is a view similar to Fig.2 showing an anchoring pin of somewhat different form and Fig. 6 is aview illustrating the invention applied to a molar tooth.

In the drawings, the tooth is indicated at 1 and the backing or plate at2. The tooth is formed with a cavity 3 extending from the part 4 whichmay be termed the root of the tooth through the greater portion of itslength and with a horizontal passage 5 which extends from the cavity 3to the back or lingual surface 6 of the tooth and receives an anchoringpin 10. This pin, as will be seen from Figs. 2 and 4, is substantiallyfiat and is provided with two prongs forming a convenient means ofattaching the tooth to the backing, although anchoring pins of othershapes may be employed if desired. Said anchoring pin is held inposition by a locking pin 11 which is lo cated in the longitudinalcavity 3. This cavity 3 extends beyond the passage 5 and consequentlythe locking pin 11 which passes through an orifice 12 in the anchoringpin 10 abuts against the material of the tooth above and below theanchoring pin and holds the latter securely in position.

The tooth is attached to the backing or base in the usual manner andduring the process of vulcanization the parts of the cavity 3 andhorizontal passage 5 which are not occupied by the anchoring pin andlooking pin respectively will be filled with the material of which thebacking is composed, the main strength of the anchorage being howeverobtained by means of the anchoring in. It will be obvious, and it isalso clear from the drawing that the cavities 3 and 5 need only be avery little larger than the sizes of the pins which they are to contain.The thickness of the tooth will therefore be suflicient to prevent anypossible discoloration or darkening of the same by reason of thepresence of the pin or material of the backing within its cavity. Itwill be furthermore observed that with this construction of tooth, thebridge piece 8 above the anchoring pin (see Fig. 1) is very strong andis well able to withstand the strain due to the pressure of the lockingpin at this point.

Referring now to Fig. 5, the anchoring pin indicated at 10 is ofsomewhat different form to that hereinbefore described and consists of apiece of wire bent to a U shape, the bent portion being received in thehorizontal passage 5 of the tooth and the looking pin 11 passing withinthe said bent portion as shown.

In Fig. 6 the invention is shown applied to a molar tooth the anchoringpin 10 being secured by the locking pin 11 in a similar manner to thathereinbefore described. The communicating passages 3 and 5 will usuallybe arranged approximately perpendicular to each other but in someinstances as in the molar tooth shown in Fig. 6 for example, they maymeet at an acute angle this being a variation included Within the scopeof the invention.

The teeth shown in Figs. 1 and 6 of the drawing are preferably put uponthe market for sale to mechanical dentists With the anchoring andlocking pins attached, in which case the locking pin is preferablysecured in position. in the cavity 3 by suitable cement so as to preventany of the parts being lost.

7 e claim as our invention:

1. In an artificial denture, a backing, an artificial tooth having anopening formed on the back or lingual surface thereof Which is closed bythe backing when the tooth is.

secured thereto, an anchor adapted to be partially embedded in thebacking and pro jectinginto said opening when the tooth is in place onthe backing, and a removable locking pin located in a second passage inthe tooth and passing through the anchor.

2. In an artificial denture, a backing,'an artificial tooth having anopening formed in the lingual surface thereof which is closed by thebacking when the tooth is in place thereon, a bifurcated anchor havingits bifurcated end embedded in the backing and Copies of this patent maybe obtained for adapted to project into the opening in the tooth, and aremovable locklng pin located in a second passage of the tooth andpassing through the anchor, said anchor adapted to tooth, and a backingin Which the projecting portion ofthe anchor is embedded dur ing theoperation of securing the tooth thereto, said backing being arranged toclose 1 the open end of said passages.

In testimony whereof We have hereiuito subscribed our names this 20thday of December 1911.

DAVID IVILLIAM BLUNDELL. JOHN HENRY MILLS. ALFRED THOMAS MAGUIRE.

Witnesses EUSTACE H. BARKER, ARTHUR T. VVAGHORN.

five cents each, by addressing the Commissioner of Patents, Washington,D. G.

